Water jet surgery has been used for some time in liver surgery, as this organ has tissue structures of different firmness (parenchyma, blood vessels and bile ducts) unlike any other organs and the applied water jet separates the tissue being cut (parenchyma) yet leaves the blood vessels and bile ducts undamaged. Naturally, precise control of the cutting pressure is required for this type of operation.
A further problem with water jet surgery is that the cutting medium must be totally sterile (e.g. Ringer solution), as the liquid comes into contact with body tissue in the closest and most intensive way possible. Ordinary problems such as high reliability, simplicity and economic manufacture must also be considered.
Medical pumps for water jet surgery are known, for example, from U.S. Pat. No. 6,216,573 B1 and DE 203 09 616 U1, which comprise an exchangeable pump unit for single use, which can be connected to pump actuating devices. Changing of the pump devices is, however, very costly with the known setups. As relatively large forces are needed to generate high pressure with sufficient flow, the devices for connection of the pump device to the pump actuating devices must be very substantial so that they can maintain a “firm hold” on the pump device during operation.